Microalgal-based macro-hollow loofah fiber bio-composite for methylene blue removal: A promising step for a green adsorbent.

This study looked into how well the macro-hollow loofah fiber with and without the bio-attaching with green microalga (Chlamydomonas reinhardtii OR242521) was applied methylene blue elimination from water. Based on the results, the biosorption capacity of loofah sponge for methylene blue significantly increased with the increase of contact time, weight of microalgal biofilm, and methylene blue concentration. The maximum biosorption capacity was achieved after 120 min, after 0.042 mgg-1 biofilm weight, and MB concentration of 140 mgL-1. Furthermore, methylene blue's biosorption capacity was strongly affected by pH, reaching its maximum at pH 7. The biosorption capacity of the bio-attached loofah sponge was much higher than that of the loofah sponge, revealing that the microalgae bio-attachment enhanced the biosorption capacity of the loofah sponge. At the end of the MB biosorption process, the used bio-attached loofah sponge can still be utilized once more for the same purpose after the desorption of MB but with a lower biosorption capacity. Furthermore, the loofah sponge could also be applied as a bio-sorbent after domestic use. According to this study, the loofah sponge with or without algal biofilm attachment could be applied as a low-cost efficient bio-sorbent for methylene blue removal from water. However, the loofah sponge's ability for biosorption was dramatically increased by the bio-attachment of microalgae, making it a more potent bio-sorbent. Likewise, this study offers insights into the variables influencing the biosorption capacity of loofah sponges and bio-attached loofah sponges, which could be beneficial for enhancing the biosorption processes.

Neoteric approach for efficient eco-friendly dye removal and recovery using algal-polymer biosorbent sheets: Characterization, factorial design, equilibrium and kinetics.

A new approach of algal-polymer -sheets was performed by the embedding of two algal seaweeds (Ulva fasciata and Sargassum dentifolium) into cellulose acetate (CA) polymer forming two types of cellulose acetate; Ulva (CA-U) and Sargassum (CA-S) sheets. Afterward, the two sheets were characterized then subjected to 3-Rs evaluation (Removal, Recovery, and Reuse) of methylene blue dye (MB). Characterization data exhibited good properties for biosorption process. Algal biosorbents achieved more than twice biosorption capacity (Qmax) after the embedding into the polymer sheet. Additionally, according to factorial design data, the contact time and the dose of biosorbents had positive effects on the biosorption in the two sheets. Freundlich, Langmuir, and pseudo-second order models displayed good represented data in the two sheets. Furthermore, the two sheets (CA-U, followed by CA-S sheet) were successfully given more than 98% adsorption of 273 mg/l MB concentration. Moreover, the recovery and reuse data proved that the two sheets can be performed in good behavior for more than three cycles.

Development of biological macroalgae lignins using copper based metal-organic framework for selective adsorption of cationic dye from mixed dyes.

The chemical compositions of macroalgae are protein; cholesterol, fatty acid, and lignin which mostly construct from hydroxyl and amine groups. The lignin as a key structure in the tissues of macroalgae was modified using the sulfation pathway. A novel environmental friendly adsorbent Cu-BTC@Algal was synthesized by incorporated Cu-BTC nanoparticles onto sulphated-Macroalgae biomass under solvothermal conditions and characterized by XRD, FTIR, and N2 adsorption-desorption isotherms. The removal rate of Cu-BTC@Algal was quite greater than that of Cu-BTC, showing that the adsorption performance of porous Cu-BTC can be improved through the modification of algal. Further study revealed that Cu-BTC@Algal exhibited a fast adsorption rate and selective adsorption ability towards the cationic dyes in aqueous solution. The removal rate was up to 97% for cationic dyes methylene blue (MB) and 68% for methyl orange (MO) at intervals 10 min. The influences including initial concentration, and contact time of MB/MO adsorption onto modified algal biomass, Cu-BTC and Cu-BTC@Algal were investigated in detail. The kinetic study indicated that the adsorption of MB/MO onto Cu-BTC@Algal followed the pseudo second-order model. The isotherm obtained from experimental data fitted the Langmuir model, yielding maximum adsorption capacity of 42, 73 and 162 mg g-1 for algal, Cu-BTC and Cu-BTC@Algal, respectively.

Eco-friendly complementary biosorption process of methylene blue using micro-sized dried biosorbents of two macro-algal species (Ulva fasciata and Sargassum dentifolium): Full factorial design, equilibrium, and kinetic studies.

Finding green effective methods for dye removal from wastewater created an important interest in comparison to conventional methods. The aim of the present work was directed to study micro grinded dried biomass of two macro-algal species, Ulva fasciata and Sargassum dentifolium as complementary biosorbent materials for effective methylene blue (MB) removal from waste water. The two macro-algal species were collected, dried, and grinded by ball mill to get the micro size. After that, the biosorbent materials were characterized by FT-IR, TEM, and DLS. Furthermore, Full Factorial Design was applied to determine the optimum conditions that maximize the MB adsorption efficiency. Ulva fasciata biosorbent material was achieved the highest MB adsorption capacity, 97% of 328 mg/l MB with a maximum adsorption capacity (qmax) of 244 mg/g in comparison to the Sargassum dentifolium, 85.6% of 26 mg/l MB with (qmax) of 66.6 mg/g. Based on Factorial Design data the main effects of the Ulva biosorbent exhibited that both time & biosorbent dose had a positive effect on biosorption and both pH & MB concentrations have a negative effect, on the other hand, no temperature effect on both biosorbents. Point of zero charge (pHpzc) was recorded at pH 6.7 and 9 for Ulva and Sargassum biosorbents, respectively. The obtained results suggested that the two macro-algal species can be used in a complementary consecutive process where Ulva fasciata started first and followed by Sargassum dentifolium. The complementary treatment process achieved efficiency of 99.2% adsorption of 300 mg/l MB concentration. Moreover, the kinetic data suggested that the adsorption of MB follows the pseudo-second order model.